But the finding is a posthumous one, as Luna, who gained celebrity after taking up residence near the village, was killed in a collision with a tugboat's propeller in March.

The accident happened in Nootka Sound on the west coast of Vancouver Island (map of British Columbia). Luna had lived there since 2001 after becoming separated from his pod as a youngster.

Researchers say an analysis of recordings of Luna's underwater calls confirms that the popular orcawhich often followed boats and interacted with local residentshas left behind an important scientific legacy.

"Luna has certainly helped to increase our knowledge of how killer whales learn their extensive repertoires, which are specific to each pod or family group," said researcher Andrew Foote of the University of Durham in England.

"I hope this [study] also demonstrates some of Luna's individuality," he added.

The findings are published in the latest issue of the journal Biology Letters.

All Bark

Acoustic recordings of Luna made in the fall of 2003 and March of 2004 were found to include noises that sound like sea lion barks.

While California sea lions also live in Nootka Sound, the Luna recordings ranged to a frequency of more than 10 kilohertzsignificantly higher than those documented for sea lion noises.